Due in part to advances in manufacturing of hard disk drives (HDDs), such as higher recording densities and lower costs, the HDD has spread from an external recording device for a large-scale computer to playing a major role in digital information recording media centered in the information technology (IT) field. As shown in FIG. 5, a HDD is constructed from a magnetic disk 1 for recording magnetic information and a magnetic head slider 3 installed at the tip of a gimbal 2. In this structure, magnetic information is read from and written to the magnetic disk 1 while the magnetic head slider 3 is flying just barely above the recording medium on the order of nanometers above the magnetic disk 1 being rotated by a spindle motor.
To achieve higher recording densities, the recording area per bit on the magnetic disk 1 must be reduced, and as a result, perpendicular magnetic recording methods for implementing this become practical. In order to improve the recording density in perpendicular magnetic recording methods, in addition to high precision finishing of the element height of a read element embedded in the magnetic head slider 3, the element height of the write element must be finished with a high degree of precision. In addition to a resistance detecting element for detecting the element height for use by the read element, a resistance detecting element for detecting the element height for use by the write element may also be formed according to some conventional methods. Technologies are also being developed to conduct high precision finishing of the element height of the write element based on the element heights derived from the resistance values of the resistance detecting elements described above in the air bearing surface polishing process.